Have 2 years on mine with a stock air box and have yet to have a problem with it . Ride revy 30 + days a year .been riding with 2011 -2016 ktms and no problems with them either ...
I finally got some heavier weights and got them in stalled and it has not made any difference. Gonna try a new fuel filter and check the reeds I guess .
Sled runs good up till 7900 rpm then it falls on its face . Can't get it to hit the 8150 mark .I cleaned the exhaust valves and check for cracked in the rubbers . All was good along with the clutch spring isnot broke .